Control apparatus



July 25, 1933. M|LL$ ET AL 1,919,446

CONTROL APPARATUS Filed July 51, 1928 2 Sheets-Sheet l Ink 2973i?) 15' flerlryml/m Mia? fiaior ge Z(Z Lrwsl y & E M p M a flt 6 25, 1933. B. M. MELLS ET AL 1,919,446

CONTROL APPARATUS Filed July 51, 1928 2 Sheets-Sheet 2 -Patent ed July 25, 1933 UNITED STATES PATENT OFFICE BERTRAM M. MILLS AND GEORGE K. CROSSLEY, O1 PAVJTUCKET, RHODTE- TLJLIANIEJ [1S- SIGNORS TO THE STANDARD ENGINEERING WORKS,

ISLAND, .A. CORPORATION OF PAYVTTJCKET, BHODE CONTROL APPARATUS Application filed July 31,

This invention pertains to automatic regulators, and more particularly to humidity regulators such as are commonly employed for controlling the action of moistening, drying, heating and refrigerating apparatus and the like. Such regulators usually comprise an element which is sensitively responsive to variations in the moisture content of the air, and by its response to such variations initiates directly or indirectly the operation of means of suitable character for bringing about the desired atmospheric condition, for example, a predetermined per cent humidity.

Devices for indicating, recording, or regulating the moisture content of the air have long been known, but while theoretically and for some purposes at least practically useful,

vsuch devices have not in all cases been wholly satisfactory. Thus in many instances the apparatus is sluggish in operation andlags far behind changes in atmospheric conditions; in some such apparatus the parts are so delicate that they will not long withstand the effects of constant vibration such as occurs in many industrial establishments; other devices fail to function when exposed to the accumulation of lint and other dust present in cotton, flour, or other mills or factories; while in many cases the devices are complex, costly, and require frequent and skilled attention to keep them in operative condition.

The present invention provides a humid ity regulator of extremely simple construction which may be built at relatively low .cost; which contains few moving parts, which is quick and very sensitively responsive to moisture variations; which is sturdy and durable and capable of long continued operation under adverse conditions, for example when subjected to heavy vibration, a dusty and lint laden atmosphere, or inattention and lack of care; and which is reliable and substantially fool-proof.

In accordance with this invention the moisture responsive element is freely exposed to the atmosphere of the room, duct, or compartment, being guarded if desired against physical injury. by appropriate 1928. Serial No. 296,608.

switch, which in turn operates or controls the operation of air moistening or drying apparatus as, for example, by moving I l operating fans, or determining the operation of spray heads nozzles, all in a manner fai'iiliar to those skilled in the art. While such magnetic relay means is desirable, we contcmalate at the present invention is of broader uti y and may be associated, for example, with meumatic or other flu actuated relay devices or, in fact, may directly control r actuate the moisture varying elei'nents if desired. iile we have ierein for conv nience made reference to the control of mois .re as the primary function of our novel apparatus, it is to be understood that it may thus bemployed as the indirect means for varying temperature or other physical condi ions and that while ve have referred to a moi ire responsive element as the primary actuating means, we contemplate that such actuating means may be of such a nature as to respond to the presence of other substances in the air when water vapor, for example, certain specific gases or noiraqueous vapors, and in any case that the ultimate apparatus controlled by such actuating means will be of a character appropriate to the desired end.

In the accompanying drawings we have illustrated one embodiment of our invention by way of example, and in the drawings,

Fig. 1 is a front elevation of the apparatus showing the door to the casing or housing closed;

Fig. 2 is front elevation, partly broken away, showing the housing or casing with its door fully open;

Fig. 3 is a fragmentary section, to larger scale, substantially on the line 33 of Fig. 2;

Fig. 41 is a fragmentary section substantially on the line 4-4: of Fig. 1; and

Fig. is a fragmentary detail section, to larger scale, substantially on the line 5-5 of Fig. 1.

Referring to the drawings, the numeral 1 indicates generally a housing or casing forming a support for our novel apparatus and enclosing certain portions thereof. This housing may be made of any suitable material, fo. example sheet metal, and as here shown comprises the box-like rear or base portion 2 and the cover 3 secured to the base portion by means of hinges 4. The base or rear portion 2 is intended to be secured against a wall or other suitable support by suitable fasteners, brackets, or the like, and this rear por 1011 forms a container for the relay device 5 (Fig. 2). This relay device may be of any suitable character such as is commonly employed in the art and which is adapted to receive the relatively feeble impulses resulting from the movement of the moisture responsive element and to transmit such feeble impulses into force of suiiicient magnitude to actuate the ultimate controlling devices through which the moisture or I or conditions to be regulated are conor varied. This 1y device may, for examp be of pneumatic character havsuit I and readily movable valves w h control tie operation of larger valves or, as here illustrated, the relay may magnetic or electrical type in which a l e current energizes a magnet or solenoid h in turn operates a switch in a power unit. Under some circumstances such relay device may constitute the immediate means fer operating the moisture controllin -=.pparatus, and in referri g to a relay device we wish it to be understood that we intend to incluce all such arrangements through which the movements of the regulater parts are transmitted to the moisture controlling apparatus.

In accordance with our present invention we mount a br cket 6 on the inside of the cover 8, such bracket having a projecting p "ot pin 7 encircled by ball bearings 8 upon which is mounted a bell crank lever 9. As snown this bell crank lever is arranged to swing in a substantially vertical plane, the bel bear permittlng the lever to swing stantially vertical arm 11. The arm 10 is provided with a counterweight 12 and with a boss 13 projecting outwardly through an opening 13 in the door 3.

The upper part of the arm 11 consists of a metallic member 1% secured to the lower part of the arm by an electrically insulating coupling 15. At its upper end the part 1 1 carries a metal roller 16 preferably mounted upon ball bearings 17 (Fig. 3). The roller 16 is adapted to engage a metallic guide rail or contact plate 18 mounted on an insulatitng block 19 secured to the inner surface of the cover 3. The block 19 preferably has a boss 19 adjacent to the end of the plate 18, said boss having an inclined cam face whose high corner 19" disposed in a plane slightly forward of the front face of plate 18. Preferably the front face of plate 18 is slightly recessed at 18. A flexible electrical conductor 20 is connected at one end to the plate 18 while its other end is secured to a terminal in the relay device 5. The insulating block 19 carries a bracket- 19 supporting an electrical contact 21 forming an abutment or stop member engageable by a contact 2-1" carried by the part 14, thereby limiting movement of the arm 11 in one direction. 'This contact member 21 is insulated from the plate 18 and is connected to one end of the electrical conductor 22 which also leads to the relay 5. A third electrical conductor 28 is connected at one end to the member 14L and also leads to the relay 5, being supported if desired at an intermediate point by a bracket 23 secured to the cover A bracket 24 (Fig. 1) is secured to and projects outwardly from the outer surface of the cover 3 and preferably a similar bracket 25 is disposed below the bracket 24. The bracket 24 is provided with an opening for the passage of a vertically adjustable rod 26. This rod is screw threaded for the reception of an adjusting nut 27 bearing upon the upper surface of the bracket Q 1, and if desired a lock nut 28 may be arranged below the bracket 24. to retain the rod 26 in adjusted position. The lower end of the rod 26 constitutes an anchorage or abutment for the upper end of the moisture responsive element.

As here shown this moisture responsive element comprises a ribbon-like strip 29 of flexible material of suitable character, such strip being permanently secured at its upper endvto a rigid clamp or clip 30 (Fig. 5) of metal or other suitable material, preferably being riveted or otherwise permanently fixed to the clip. .A similar clip 31 is secured to the lower end of the strip 29, the clips 30 and 31 constituting attaching devices whereby the strip is mounted in proper position in the apparatus. one means of detachably securing the moisture responsive element in position, we provide the clips 30 and 31 with openings for the reception of attaching screws. Thus the screw detac iably secures the clip 30 to the lower end of the rod 36 while the screw 33 detachably secures the lower clip 31 to the boss 13 on the lever arm 10.

been employed for this purpose, among them hair, rawhide, vellum, visceral membranes of both land and water animals (of which catgut, gold beaters skin, etc. may be mentioned as examples), animal sinews, silk, and silk worm gut. Such substances have long been known as equivalents for the intended purpose and we make no specific claim thereto except in combination with the other features of our invention. However, we prefer to employ a ribbon-like strip of the selected substance since such a strip, particularly if very thin, reacts more rapidly .and with less lag to moisture variations than-would a thick rod or block.

In thus referring to a ribbon-like strip we intend to include not only material which is integrally homogeneous throughout its width but also a ribbon-like band consisting of aplurality of parallelly arranged strands or fibers, since the latter arrangement, if the fibers or strands be of uniform character and relatively small diameter, functions in substantially the same way as a homogeneous strip.

Since certain visceralmembranes of animals, when properly cured, possess considerable strength, although usually quite thin and flexible, and since such substances may readily be prepared in the form of ribbonlike strip of suitable length, we prefer to employ substances of this type, and suggest gold beaters skin as satisfactory, but wish it to be understood that any of the substances above mentioned as well as other equivalent substances may be used if desired.

The operation of the above device is substantially as follows, it being assumed that the parts occupy the position shown in Fig. 2 when, for example, the moisture in the air is at a maximum, that is to say of the desired predetermined per cent humidity. Under these conditions the moisture responsive element 29 may be assumed to be of maximum length, so that the weight 12 acting upon the bell. crank lever 9 holds the contact member 21 against tie fixed contact 21, thus closing an electrical circuit includingtheparts 23,213 21, 22, and terminals, thus energizing'a magnetic switch (not shown) or other equivalent device forming part of the relay, such device, when energized directly or indirectly, stopping the operation of the air moistening apparatus.

In moving to bring the contacts 21 and 21 into eiigageiiieirt the lever 11 carries roller 16 up and over the l h point 19 of tlrbe; 19, this being perr ed by the esiliency the long lever arm, and as the roller the cam face of the boss 19 a componel 7. thrust in the the direction of the fixed contact 21 is developed, so that inadvertent sep aration of the contacts by vibration or the like is substantially prevented.

Assuming that the oer centhumidity of the air drops below predetermined desired anount, the moisture absorbent ole ment 29 will respond to tins change in at- V mospheric conditions, shorten thus 33 lever l the arm 10 of the l."*n swinging the con ra-t 21 the contact 21, thus brea J10 through the conductors roller 16 drops from hi boss 19 it engages the clone or rail 18, ant, thereby through 0011(lL the roller 16, the 20. Th closin tne air moistening apparatus 1 During the operatic paratus the e 1 the plate 18 iii l ection and in the other, but mainuning the circuit until the moisture in the a rises to w extent as to restore *h its original position w engagement with the contact 2- air moistening i. ates is age. to rest.

ire absorbat the e air, and in ianical in- .ide guard posts or s 2% out element terior of the casi g OTdGl to protect it a jury, we propose to p rods and 35- nd in the bracln and 25. These guard rods may be re by a suitable screen, althou h prei rods since icy do not app iably interf e with the free flow of air and about moisture responsive element. As above described, this moisture responsive element 1 ilacement ii j, and prorespon o olel at- 21111 L lli.

ments, c mp1, 1Q 29 1'29 tachmg devices and ab e a r hcntion to the a";

are e osed within accessible for ins 'iection, lulu-ice- The re counterbalanced lever, mounted upon ball bearings and vith a ball bearing contact roller 16 acting as a guide and support for the lon er arm of tile lever,

opposes a mi: mum rcristenc so that very slight cha 1 moisture responsive elenicn sol-bent aside fr Pn th of the readil The nt length, but ent no other lL\ adjustni the apparatus is substant y prooi against tampering by imskilieo 1;, sons.

While W nave herein shown one desirable embodiment the invention, We Wish it to be iiii cor t at vari details, for e 1C- ndc Without e invention. Vi e .lso cor isturc responsive =lc through cont that the spoom trical contact others in accordance W l employed or, it re be reoraceo a moisture r the housing,

si' rm 0 the latter arm in cl: in he 40 e my device in the 102E118 carried by the tee relay & device.

n ent outside of the housing, means operatively connecting one end of said element to the outwardly projecting member, and normally fixed but adjustable means positioning the opposite end of the moisture responsive element.

4. In apparatus of the class described, in combination a bell-crank le r mounted on anti-friction bearings to swing; freely in a substantially vertical plane, one arm of said lever being ubstantially horizontal, 2 Weight on said latter arm tending to swing the l ver in one direction, a moisture responsive element connected to said arm and under ertain conditions swinging the l'SVfiflU opposition to the veight, the lever having a substantially verti al arm, a mile mounted i a iti-friction bearings near the end of the arm, a metallic contact rail with which roller engages, a stop member with i'vnich part of the lever flitliCS electrical contact at one end of its path oi movement.

'". In rppi ratus of th class dese 'ibed, in

tion a support, a bracket carried by ipport, a lever mounted to swing on iction bearings interposed between it bracket, an antidriction roller carried by the lever, said r ller engaging a ,c iiice ei-ment carried by the srpport, said lever comprising an electrically insulated rt constituting a current closing; contact, a i c contact cngagea le by said insulated J 1 as the lever swings in one direction, beans tending to swing the lever in one diction, and moisture responsive element nected to the lever and operative under :eioain moisture conditions to swing the ever in the opposite direction.

3.111 apparatus of the character doscribcd, the combination oi a moisture responsive element, movable electrical contact means actuable thereby, a fixed contact enggz'igeeble by said movable contact means to complete an electrical circuit and stop the air moistening means when a nedeterrnrned per cent humidity has been obtained, and rigid means opposing resistance to separation oi said contacts. 

